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1# SPDX-License-Identifier: GPL-2.0-only
2#
3# Block device driver configuration
4#
5
6menuconfig MD
7 bool "Multiple devices driver support (RAID and LVM)"
8 depends on BLOCK
9 select SRCU
10 help
11 Support multiple physical spindles through a single logical device.
12 Required for RAID and logical volume management.
13
14if MD
15
16config BLK_DEV_MD
17 tristate "RAID support"
18 select BLOCK_HOLDER_DEPRECATED if SYSFS
19 help
20 This driver lets you combine several hard disk partitions into one
21 logical block device. This can be used to simply append one
22 partition to another one or to combine several redundant hard disks
23 into a RAID1/4/5 device so as to provide protection against hard
24 disk failures. This is called "Software RAID" since the combining of
25 the partitions is done by the kernel. "Hardware RAID" means that the
26 combining is done by a dedicated controller; if you have such a
27 controller, you do not need to say Y here.
28
29 More information about Software RAID on Linux is contained in the
30 Software RAID mini-HOWTO, available from
31 <https://www.tldp.org/docs.html#howto>. There you will also learn
32 where to get the supporting user space utilities raidtools.
33
34 If unsure, say N.
35
36config MD_AUTODETECT
37 bool "Autodetect RAID arrays during kernel boot"
38 depends on BLK_DEV_MD=y
39 default y
40 help
41 If you say Y here, then the kernel will try to autodetect raid
42 arrays as part of its boot process.
43
44 If you don't use raid and say Y, this autodetection can cause
45 a several-second delay in the boot time due to various
46 synchronisation steps that are part of this step.
47
48 If unsure, say Y.
49
50config MD_LINEAR
51 tristate "Linear (append) mode (deprecated)"
52 depends on BLK_DEV_MD
53 help
54 If you say Y here, then your multiple devices driver will be able to
55 use the so-called linear mode, i.e. it will combine the hard disk
56 partitions by simply appending one to the other.
57
58 To compile this as a module, choose M here: the module
59 will be called linear.
60
61 If unsure, say Y.
62
63config MD_RAID0
64 tristate "RAID-0 (striping) mode"
65 depends on BLK_DEV_MD
66 help
67 If you say Y here, then your multiple devices driver will be able to
68 use the so-called raid0 mode, i.e. it will combine the hard disk
69 partitions into one logical device in such a fashion as to fill them
70 up evenly, one chunk here and one chunk there. This will increase
71 the throughput rate if the partitions reside on distinct disks.
72
73 Information about Software RAID on Linux is contained in the
74 Software-RAID mini-HOWTO, available from
75 <https://www.tldp.org/docs.html#howto>. There you will also
76 learn where to get the supporting user space utilities raidtools.
77
78 To compile this as a module, choose M here: the module
79 will be called raid0.
80
81 If unsure, say Y.
82
83config MD_RAID1
84 tristate "RAID-1 (mirroring) mode"
85 depends on BLK_DEV_MD
86 help
87 A RAID-1 set consists of several disk drives which are exact copies
88 of each other. In the event of a mirror failure, the RAID driver
89 will continue to use the operational mirrors in the set, providing
90 an error free MD (multiple device) to the higher levels of the
91 kernel. In a set with N drives, the available space is the capacity
92 of a single drive, and the set protects against a failure of (N - 1)
93 drives.
94
95 Information about Software RAID on Linux is contained in the
96 Software-RAID mini-HOWTO, available from
97 <https://www.tldp.org/docs.html#howto>. There you will also
98 learn where to get the supporting user space utilities raidtools.
99
100 If you want to use such a RAID-1 set, say Y. To compile this code
101 as a module, choose M here: the module will be called raid1.
102
103 If unsure, say Y.
104
105config MD_RAID10
106 tristate "RAID-10 (mirrored striping) mode"
107 depends on BLK_DEV_MD
108 help
109 RAID-10 provides a combination of striping (RAID-0) and
110 mirroring (RAID-1) with easier configuration and more flexible
111 layout.
112 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
113 be the same size (or at least, only as much as the smallest device
114 will be used).
115 RAID-10 provides a variety of layouts that provide different levels
116 of redundancy and performance.
117
118 RAID-10 requires mdadm-1.7.0 or later, available at:
119
120 https://www.kernel.org/pub/linux/utils/raid/mdadm/
121
122 If unsure, say Y.
123
124config MD_RAID456
125 tristate "RAID-4/RAID-5/RAID-6 mode"
126 depends on BLK_DEV_MD
127 select RAID6_PQ
128 select LIBCRC32C
129 select ASYNC_MEMCPY
130 select ASYNC_XOR
131 select ASYNC_PQ
132 select ASYNC_RAID6_RECOV
133 help
134 A RAID-5 set of N drives with a capacity of C MB per drive provides
135 the capacity of C * (N - 1) MB, and protects against a failure
136 of a single drive. For a given sector (row) number, (N - 1) drives
137 contain data sectors, and one drive contains the parity protection.
138 For a RAID-4 set, the parity blocks are present on a single drive,
139 while a RAID-5 set distributes the parity across the drives in one
140 of the available parity distribution methods.
141
142 A RAID-6 set of N drives with a capacity of C MB per drive
143 provides the capacity of C * (N - 2) MB, and protects
144 against a failure of any two drives. For a given sector
145 (row) number, (N - 2) drives contain data sectors, and two
146 drives contains two independent redundancy syndromes. Like
147 RAID-5, RAID-6 distributes the syndromes across the drives
148 in one of the available parity distribution methods.
149
150 Information about Software RAID on Linux is contained in the
151 Software-RAID mini-HOWTO, available from
152 <https://www.tldp.org/docs.html#howto>. There you will also
153 learn where to get the supporting user space utilities raidtools.
154
155 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
156 compile this code as a module, choose M here: the module
157 will be called raid456.
158
159 If unsure, say Y.
160
161config MD_MULTIPATH
162 tristate "Multipath I/O support (deprecated)"
163 depends on BLK_DEV_MD
164 help
165 MD_MULTIPATH provides a simple multi-path personality for use
166 the MD framework. It is not under active development. New
167 projects should consider using DM_MULTIPATH which has more
168 features and more testing.
169
170 If unsure, say N.
171
172config MD_FAULTY
173 tristate "Faulty test module for MD (deprecated)"
174 depends on BLK_DEV_MD
175 help
176 The "faulty" module allows for a block device that occasionally returns
177 read or write errors. It is useful for testing.
178
179 In unsure, say N.
180
181
182config MD_CLUSTER
183 tristate "Cluster Support for MD"
184 depends on BLK_DEV_MD
185 depends on DLM
186 default n
187 help
188 Clustering support for MD devices. This enables locking and
189 synchronization across multiple systems on the cluster, so all
190 nodes in the cluster can access the MD devices simultaneously.
191
192 This brings the redundancy (and uptime) of RAID levels across the
193 nodes of the cluster. Currently, it can work with raid1 and raid10
194 (limited support).
195
196 If unsure, say N.
197
198source "drivers/md/bcache/Kconfig"
199
200config BLK_DEV_DM_BUILTIN
201 bool
202
203config BLK_DEV_DM
204 tristate "Device mapper support"
205 select BLOCK_HOLDER_DEPRECATED if SYSFS
206 select BLK_DEV_DM_BUILTIN
207 select BLK_MQ_STACKING
208 depends on DAX || DAX=n
209 help
210 Device-mapper is a low level volume manager. It works by allowing
211 people to specify mappings for ranges of logical sectors. Various
212 mapping types are available, in addition people may write their own
213 modules containing custom mappings if they wish.
214
215 Higher level volume managers such as LVM2 use this driver.
216
217 To compile this as a module, choose M here: the module will be
218 called dm-mod.
219
220 If unsure, say N.
221
222config DM_DEBUG
223 bool "Device mapper debugging support"
224 depends on BLK_DEV_DM
225 help
226 Enable this for messages that may help debug device-mapper problems.
227
228 If unsure, say N.
229
230config DM_BUFIO
231 tristate
232 depends on BLK_DEV_DM
233 help
234 This interface allows you to do buffered I/O on a device and acts
235 as a cache, holding recently-read blocks in memory and performing
236 delayed writes.
237
238config DM_DEBUG_BLOCK_MANAGER_LOCKING
239 bool "Block manager locking"
240 depends on DM_BUFIO
241 help
242 Block manager locking can catch various metadata corruption issues.
243
244 If unsure, say N.
245
246config DM_DEBUG_BLOCK_STACK_TRACING
247 bool "Keep stack trace of persistent data block lock holders"
248 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
249 select STACKTRACE
250 help
251 Enable this for messages that may help debug problems with the
252 block manager locking used by thin provisioning and caching.
253
254 If unsure, say N.
255
256config DM_BIO_PRISON
257 tristate
258 depends on BLK_DEV_DM
259 help
260 Some bio locking schemes used by other device-mapper targets
261 including thin provisioning.
262
263source "drivers/md/persistent-data/Kconfig"
264
265config DM_UNSTRIPED
266 tristate "Unstriped target"
267 depends on BLK_DEV_DM
268 help
269 Unstripes I/O so it is issued solely on a single drive in a HW
270 RAID0 or dm-striped target.
271
272config DM_CRYPT
273 tristate "Crypt target support"
274 depends on BLK_DEV_DM
275 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
276 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
277 select CRYPTO
278 select CRYPTO_CBC
279 select CRYPTO_ESSIV
280 help
281 This device-mapper target allows you to create a device that
282 transparently encrypts the data on it. You'll need to activate
283 the ciphers you're going to use in the cryptoapi configuration.
284
285 For further information on dm-crypt and userspace tools see:
286 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
287
288 To compile this code as a module, choose M here: the module will
289 be called dm-crypt.
290
291 If unsure, say N.
292
293config DM_SNAPSHOT
294 tristate "Snapshot target"
295 depends on BLK_DEV_DM
296 select DM_BUFIO
297 help
298 Allow volume managers to take writable snapshots of a device.
299
300config DM_THIN_PROVISIONING
301 tristate "Thin provisioning target"
302 depends on BLK_DEV_DM
303 select DM_PERSISTENT_DATA
304 select DM_BIO_PRISON
305 help
306 Provides thin provisioning and snapshots that share a data store.
307
308config DM_CACHE
309 tristate "Cache target (EXPERIMENTAL)"
310 depends on BLK_DEV_DM
311 default n
312 select DM_PERSISTENT_DATA
313 select DM_BIO_PRISON
314 help
315 dm-cache attempts to improve performance of a block device by
316 moving frequently used data to a smaller, higher performance
317 device. Different 'policy' plugins can be used to change the
318 algorithms used to select which blocks are promoted, demoted,
319 cleaned etc. It supports writeback and writethrough modes.
320
321config DM_CACHE_SMQ
322 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
323 depends on DM_CACHE
324 default y
325 help
326 A cache policy that uses a multiqueue ordered by recent hits
327 to select which blocks should be promoted and demoted.
328 This is meant to be a general purpose policy. It prioritises
329 reads over writes. This SMQ policy (vs MQ) offers the promise
330 of less memory utilization, improved performance and increased
331 adaptability in the face of changing workloads.
332
333config DM_WRITECACHE
334 tristate "Writecache target"
335 depends on BLK_DEV_DM
336 help
337 The writecache target caches writes on persistent memory or SSD.
338 It is intended for databases or other programs that need extremely
339 low commit latency.
340
341 The writecache target doesn't cache reads because reads are supposed
342 to be cached in standard RAM.
343
344config DM_EBS
345 tristate "Emulated block size target (EXPERIMENTAL)"
346 depends on BLK_DEV_DM && !HIGHMEM
347 select DM_BUFIO
348 help
349 dm-ebs emulates smaller logical block size on backing devices
350 with larger ones (e.g. 512 byte sectors on 4K native disks).
351
352config DM_ERA
353 tristate "Era target (EXPERIMENTAL)"
354 depends on BLK_DEV_DM
355 default n
356 select DM_PERSISTENT_DATA
357 select DM_BIO_PRISON
358 help
359 dm-era tracks which parts of a block device are written to
360 over time. Useful for maintaining cache coherency when using
361 vendor snapshots.
362
363config DM_CLONE
364 tristate "Clone target (EXPERIMENTAL)"
365 depends on BLK_DEV_DM
366 default n
367 select DM_PERSISTENT_DATA
368 help
369 dm-clone produces a one-to-one copy of an existing, read-only source
370 device into a writable destination device. The cloned device is
371 visible/mountable immediately and the copy of the source device to the
372 destination device happens in the background, in parallel with user
373 I/O.
374
375 If unsure, say N.
376
377config DM_MIRROR
378 tristate "Mirror target"
379 depends on BLK_DEV_DM
380 help
381 Allow volume managers to mirror logical volumes, also
382 needed for live data migration tools such as 'pvmove'.
383
384config DM_LOG_USERSPACE
385 tristate "Mirror userspace logging"
386 depends on DM_MIRROR && NET
387 select CONNECTOR
388 help
389 The userspace logging module provides a mechanism for
390 relaying the dm-dirty-log API to userspace. Log designs
391 which are more suited to userspace implementation (e.g.
392 shared storage logs) or experimental logs can be implemented
393 by leveraging this framework.
394
395config DM_RAID
396 tristate "RAID 1/4/5/6/10 target"
397 depends on BLK_DEV_DM
398 select MD_RAID0
399 select MD_RAID1
400 select MD_RAID10
401 select MD_RAID456
402 select BLK_DEV_MD
403 help
404 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
405
406 A RAID-5 set of N drives with a capacity of C MB per drive provides
407 the capacity of C * (N - 1) MB, and protects against a failure
408 of a single drive. For a given sector (row) number, (N - 1) drives
409 contain data sectors, and one drive contains the parity protection.
410 For a RAID-4 set, the parity blocks are present on a single drive,
411 while a RAID-5 set distributes the parity across the drives in one
412 of the available parity distribution methods.
413
414 A RAID-6 set of N drives with a capacity of C MB per drive
415 provides the capacity of C * (N - 2) MB, and protects
416 against a failure of any two drives. For a given sector
417 (row) number, (N - 2) drives contain data sectors, and two
418 drives contains two independent redundancy syndromes. Like
419 RAID-5, RAID-6 distributes the syndromes across the drives
420 in one of the available parity distribution methods.
421
422config DM_ZERO
423 tristate "Zero target"
424 depends on BLK_DEV_DM
425 help
426 A target that discards writes, and returns all zeroes for
427 reads. Useful in some recovery situations.
428
429config DM_MULTIPATH
430 tristate "Multipath target"
431 depends on BLK_DEV_DM
432 # nasty syntax but means make DM_MULTIPATH independent
433 # of SCSI_DH if the latter isn't defined but if
434 # it is, DM_MULTIPATH must depend on it. We get a build
435 # error if SCSI_DH=m and DM_MULTIPATH=y
436 depends on !SCSI_DH || SCSI
437 help
438 Allow volume managers to support multipath hardware.
439
440config DM_MULTIPATH_QL
441 tristate "I/O Path Selector based on the number of in-flight I/Os"
442 depends on DM_MULTIPATH
443 help
444 This path selector is a dynamic load balancer which selects
445 the path with the least number of in-flight I/Os.
446
447 If unsure, say N.
448
449config DM_MULTIPATH_ST
450 tristate "I/O Path Selector based on the service time"
451 depends on DM_MULTIPATH
452 help
453 This path selector is a dynamic load balancer which selects
454 the path expected to complete the incoming I/O in the shortest
455 time.
456
457 If unsure, say N.
458
459config DM_MULTIPATH_HST
460 tristate "I/O Path Selector based on historical service time"
461 depends on DM_MULTIPATH
462 help
463 This path selector is a dynamic load balancer which selects
464 the path expected to complete the incoming I/O in the shortest
465 time by comparing estimated service time (based on historical
466 service time).
467
468 If unsure, say N.
469
470config DM_MULTIPATH_IOA
471 tristate "I/O Path Selector based on CPU submission"
472 depends on DM_MULTIPATH
473 help
474 This path selector selects the path based on the CPU the IO is
475 executed on and the CPU to path mapping setup at path addition time.
476
477 If unsure, say N.
478
479config DM_DELAY
480 tristate "I/O delaying target"
481 depends on BLK_DEV_DM
482 help
483 A target that delays reads and/or writes and can send
484 them to different devices. Useful for testing.
485
486 If unsure, say N.
487
488config DM_DUST
489 tristate "Bad sector simulation target"
490 depends on BLK_DEV_DM
491 help
492 A target that simulates bad sector behavior.
493 Useful for testing.
494
495 If unsure, say N.
496
497config DM_INIT
498 bool "DM \"dm-mod.create=\" parameter support"
499 depends on BLK_DEV_DM=y
500 help
501 Enable "dm-mod.create=" parameter to create mapped devices at init time.
502 This option is useful to allow mounting rootfs without requiring an
503 initramfs.
504 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
505 format.
506
507 If unsure, say N.
508
509config DM_UEVENT
510 bool "DM uevents"
511 depends on BLK_DEV_DM
512 help
513 Generate udev events for DM events.
514
515config DM_FLAKEY
516 tristate "Flakey target"
517 depends on BLK_DEV_DM
518 help
519 A target that intermittently fails I/O for debugging purposes.
520
521config DM_VERITY
522 tristate "Verity target support"
523 depends on BLK_DEV_DM
524 select CRYPTO
525 select CRYPTO_HASH
526 select DM_BUFIO
527 help
528 This device-mapper target creates a read-only device that
529 transparently validates the data on one underlying device against
530 a pre-generated tree of cryptographic checksums stored on a second
531 device.
532
533 You'll need to activate the digests you're going to use in the
534 cryptoapi configuration.
535
536 To compile this code as a module, choose M here: the module will
537 be called dm-verity.
538
539 If unsure, say N.
540
541config DM_VERITY_VERIFY_ROOTHASH_SIG
542 def_bool n
543 bool "Verity data device root hash signature verification support"
544 depends on DM_VERITY
545 select SYSTEM_DATA_VERIFICATION
546 help
547 Add ability for dm-verity device to be validated if the
548 pre-generated tree of cryptographic checksums passed has a pkcs#7
549 signature file that can validate the roothash of the tree.
550
551 By default, rely on the builtin trusted keyring.
552
553 If unsure, say N.
554
555config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
556 bool "Verity data device root hash signature verification with secondary keyring"
557 depends on DM_VERITY_VERIFY_ROOTHASH_SIG
558 depends on SECONDARY_TRUSTED_KEYRING
559 help
560 Rely on the secondary trusted keyring to verify dm-verity signatures.
561
562 If unsure, say N.
563
564config DM_VERITY_FEC
565 bool "Verity forward error correction support"
566 depends on DM_VERITY
567 select REED_SOLOMON
568 select REED_SOLOMON_DEC8
569 help
570 Add forward error correction support to dm-verity. This option
571 makes it possible to use pre-generated error correction data to
572 recover from corrupted blocks.
573
574 If unsure, say N.
575
576config DM_SWITCH
577 tristate "Switch target support (EXPERIMENTAL)"
578 depends on BLK_DEV_DM
579 help
580 This device-mapper target creates a device that supports an arbitrary
581 mapping of fixed-size regions of I/O across a fixed set of paths.
582 The path used for any specific region can be switched dynamically
583 by sending the target a message.
584
585 To compile this code as a module, choose M here: the module will
586 be called dm-switch.
587
588 If unsure, say N.
589
590config DM_LOG_WRITES
591 tristate "Log writes target support"
592 depends on BLK_DEV_DM
593 help
594 This device-mapper target takes two devices, one device to use
595 normally, one to log all write operations done to the first device.
596 This is for use by file system developers wishing to verify that
597 their fs is writing a consistent file system at all times by allowing
598 them to replay the log in a variety of ways and to check the
599 contents.
600
601 To compile this code as a module, choose M here: the module will
602 be called dm-log-writes.
603
604 If unsure, say N.
605
606config DM_INTEGRITY
607 tristate "Integrity target support"
608 depends on BLK_DEV_DM
609 select BLK_DEV_INTEGRITY
610 select DM_BUFIO
611 select CRYPTO
612 select CRYPTO_SKCIPHER
613 select ASYNC_XOR
614 select DM_AUDIT if AUDIT
615 help
616 This device-mapper target emulates a block device that has
617 additional per-sector tags that can be used for storing
618 integrity information.
619
620 This integrity target is used with the dm-crypt target to
621 provide authenticated disk encryption or it can be used
622 standalone.
623
624 To compile this code as a module, choose M here: the module will
625 be called dm-integrity.
626
627config DM_ZONED
628 tristate "Drive-managed zoned block device target support"
629 depends on BLK_DEV_DM
630 depends on BLK_DEV_ZONED
631 select CRC32
632 help
633 This device-mapper target takes a host-managed or host-aware zoned
634 block device and exposes most of its capacity as a regular block
635 device (drive-managed zoned block device) without any write
636 constraints. This is mainly intended for use with file systems that
637 do not natively support zoned block devices but still want to
638 benefit from the increased capacity offered by SMR disks. Other uses
639 by applications using raw block devices (for example object stores)
640 are also possible.
641
642 To compile this code as a module, choose M here: the module will
643 be called dm-zoned.
644
645 If unsure, say N.
646
647config DM_AUDIT
648 bool "DM audit events"
649 depends on AUDIT
650 help
651 Generate audit events for device-mapper.
652
653 Enables audit logging of several security relevant events in the
654 particular device-mapper targets, especially the integrity target.
655
656endif # MD
1# SPDX-License-Identifier: GPL-2.0-only
2#
3# Block device driver configuration
4#
5
6menuconfig MD
7 bool "Multiple devices driver support (RAID and LVM)"
8 depends on BLOCK
9 help
10 Support multiple physical spindles through a single logical device.
11 Required for RAID and logical volume management.
12
13if MD
14
15config BLK_DEV_MD
16 tristate "RAID support"
17 select BLOCK_HOLDER_DEPRECATED if SYSFS
18 select BUFFER_HEAD
19 # BLOCK_LEGACY_AUTOLOAD requirement should be removed
20 # after relevant mdadm enhancements - to make "names=yes"
21 # the default - are widely available.
22 select BLOCK_LEGACY_AUTOLOAD
23 help
24 This driver lets you combine several hard disk partitions into one
25 logical block device. This can be used to simply append one
26 partition to another one or to combine several redundant hard disks
27 into a RAID1/4/5 device so as to provide protection against hard
28 disk failures. This is called "Software RAID" since the combining of
29 the partitions is done by the kernel. "Hardware RAID" means that the
30 combining is done by a dedicated controller; if you have such a
31 controller, you do not need to say Y here.
32
33 More information about Software RAID on Linux is contained in the
34 Software RAID mini-HOWTO, available from
35 <https://www.tldp.org/docs.html#howto>. There you will also learn
36 where to get the supporting user space utilities raidtools.
37
38 If unsure, say N.
39
40config MD_AUTODETECT
41 bool "Autodetect RAID arrays during kernel boot"
42 depends on BLK_DEV_MD=y
43 default y
44 help
45 If you say Y here, then the kernel will try to autodetect raid
46 arrays as part of its boot process.
47
48 If you don't use raid and say Y, this autodetection can cause
49 a several-second delay in the boot time due to various
50 synchronisation steps that are part of this step.
51
52 If unsure, say Y.
53
54config MD_BITMAP_FILE
55 bool "MD bitmap file support (deprecated)"
56 default y
57 help
58 If you say Y here, support for write intent bitmaps in files on an
59 external file system is enabled. This is an alternative to the internal
60 bitmaps near the MD superblock, and very problematic code that abuses
61 various kernel APIs and can only work with files on a file system not
62 actually sitting on the MD device.
63
64config MD_RAID0
65 tristate "RAID-0 (striping) mode"
66 depends on BLK_DEV_MD
67 help
68 If you say Y here, then your multiple devices driver will be able to
69 use the so-called raid0 mode, i.e. it will combine the hard disk
70 partitions into one logical device in such a fashion as to fill them
71 up evenly, one chunk here and one chunk there. This will increase
72 the throughput rate if the partitions reside on distinct disks.
73
74 Information about Software RAID on Linux is contained in the
75 Software-RAID mini-HOWTO, available from
76 <https://www.tldp.org/docs.html#howto>. There you will also
77 learn where to get the supporting user space utilities raidtools.
78
79 To compile this as a module, choose M here: the module
80 will be called raid0.
81
82 If unsure, say Y.
83
84config MD_RAID1
85 tristate "RAID-1 (mirroring) mode"
86 depends on BLK_DEV_MD
87 help
88 A RAID-1 set consists of several disk drives which are exact copies
89 of each other. In the event of a mirror failure, the RAID driver
90 will continue to use the operational mirrors in the set, providing
91 an error free MD (multiple device) to the higher levels of the
92 kernel. In a set with N drives, the available space is the capacity
93 of a single drive, and the set protects against a failure of (N - 1)
94 drives.
95
96 Information about Software RAID on Linux is contained in the
97 Software-RAID mini-HOWTO, available from
98 <https://www.tldp.org/docs.html#howto>. There you will also
99 learn where to get the supporting user space utilities raidtools.
100
101 If you want to use such a RAID-1 set, say Y. To compile this code
102 as a module, choose M here: the module will be called raid1.
103
104 If unsure, say Y.
105
106config MD_RAID10
107 tristate "RAID-10 (mirrored striping) mode"
108 depends on BLK_DEV_MD
109 help
110 RAID-10 provides a combination of striping (RAID-0) and
111 mirroring (RAID-1) with easier configuration and more flexible
112 layout.
113 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
114 be the same size (or at least, only as much as the smallest device
115 will be used).
116 RAID-10 provides a variety of layouts that provide different levels
117 of redundancy and performance.
118
119 RAID-10 requires mdadm-1.7.0 or later, available at:
120
121 https://www.kernel.org/pub/linux/utils/raid/mdadm/
122
123 If unsure, say Y.
124
125config MD_RAID456
126 tristate "RAID-4/RAID-5/RAID-6 mode"
127 depends on BLK_DEV_MD
128 select RAID6_PQ
129 select LIBCRC32C
130 select ASYNC_MEMCPY
131 select ASYNC_XOR
132 select ASYNC_PQ
133 select ASYNC_RAID6_RECOV
134 help
135 A RAID-5 set of N drives with a capacity of C MB per drive provides
136 the capacity of C * (N - 1) MB, and protects against a failure
137 of a single drive. For a given sector (row) number, (N - 1) drives
138 contain data sectors, and one drive contains the parity protection.
139 For a RAID-4 set, the parity blocks are present on a single drive,
140 while a RAID-5 set distributes the parity across the drives in one
141 of the available parity distribution methods.
142
143 A RAID-6 set of N drives with a capacity of C MB per drive
144 provides the capacity of C * (N - 2) MB, and protects
145 against a failure of any two drives. For a given sector
146 (row) number, (N - 2) drives contain data sectors, and two
147 drives contains two independent redundancy syndromes. Like
148 RAID-5, RAID-6 distributes the syndromes across the drives
149 in one of the available parity distribution methods.
150
151 Information about Software RAID on Linux is contained in the
152 Software-RAID mini-HOWTO, available from
153 <https://www.tldp.org/docs.html#howto>. There you will also
154 learn where to get the supporting user space utilities raidtools.
155
156 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
157 compile this code as a module, choose M here: the module
158 will be called raid456.
159
160 If unsure, say Y.
161
162config MD_CLUSTER
163 tristate "Cluster Support for MD"
164 depends on BLK_DEV_MD
165 depends on DLM
166 default n
167 help
168 Clustering support for MD devices. This enables locking and
169 synchronization across multiple systems on the cluster, so all
170 nodes in the cluster can access the MD devices simultaneously.
171
172 This brings the redundancy (and uptime) of RAID levels across the
173 nodes of the cluster. Currently, it can work with raid1 and raid10
174 (limited support).
175
176 If unsure, say N.
177
178source "drivers/md/bcache/Kconfig"
179
180config BLK_DEV_DM_BUILTIN
181 bool
182
183config BLK_DEV_DM
184 tristate "Device mapper support"
185 select BLOCK_HOLDER_DEPRECATED if SYSFS
186 select BLK_DEV_DM_BUILTIN
187 select BLK_MQ_STACKING
188 depends on DAX || DAX=n
189 help
190 Device-mapper is a low level volume manager. It works by allowing
191 people to specify mappings for ranges of logical sectors. Various
192 mapping types are available, in addition people may write their own
193 modules containing custom mappings if they wish.
194
195 Higher level volume managers such as LVM2 use this driver.
196
197 To compile this as a module, choose M here: the module will be
198 called dm-mod.
199
200 If unsure, say N.
201
202config DM_DEBUG
203 bool "Device mapper debugging support"
204 depends on BLK_DEV_DM
205 help
206 Enable this for messages that may help debug device-mapper problems.
207
208 If unsure, say N.
209
210config DM_BUFIO
211 tristate
212 depends on BLK_DEV_DM
213 help
214 This interface allows you to do buffered I/O on a device and acts
215 as a cache, holding recently-read blocks in memory and performing
216 delayed writes.
217
218config DM_DEBUG_BLOCK_MANAGER_LOCKING
219 bool "Block manager locking"
220 depends on DM_BUFIO
221 help
222 Block manager locking can catch various metadata corruption issues.
223
224 If unsure, say N.
225
226config DM_DEBUG_BLOCK_STACK_TRACING
227 bool "Keep stack trace of persistent data block lock holders"
228 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
229 select STACKTRACE
230 help
231 Enable this for messages that may help debug problems with the
232 block manager locking used by thin provisioning and caching.
233
234 If unsure, say N.
235
236config DM_BIO_PRISON
237 tristate
238 depends on BLK_DEV_DM
239 help
240 Some bio locking schemes used by other device-mapper targets
241 including thin provisioning.
242
243source "drivers/md/persistent-data/Kconfig"
244
245config DM_UNSTRIPED
246 tristate "Unstriped target"
247 depends on BLK_DEV_DM
248 help
249 Unstripes I/O so it is issued solely on a single drive in a HW
250 RAID0 or dm-striped target.
251
252config DM_CRYPT
253 tristate "Crypt target support"
254 depends on BLK_DEV_DM
255 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
256 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
257 select CRYPTO
258 select CRYPTO_CBC
259 select CRYPTO_ESSIV
260 help
261 This device-mapper target allows you to create a device that
262 transparently encrypts the data on it. You'll need to activate
263 the ciphers you're going to use in the cryptoapi configuration.
264
265 For further information on dm-crypt and userspace tools see:
266 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
267
268 To compile this code as a module, choose M here: the module will
269 be called dm-crypt.
270
271 If unsure, say N.
272
273config DM_SNAPSHOT
274 tristate "Snapshot target"
275 depends on BLK_DEV_DM
276 select DM_BUFIO
277 help
278 Allow volume managers to take writable snapshots of a device.
279
280config DM_THIN_PROVISIONING
281 tristate "Thin provisioning target"
282 depends on BLK_DEV_DM
283 select DM_PERSISTENT_DATA
284 select DM_BIO_PRISON
285 help
286 Provides thin provisioning and snapshots that share a data store.
287
288config DM_CACHE
289 tristate "Cache target (EXPERIMENTAL)"
290 depends on BLK_DEV_DM
291 default n
292 select DM_PERSISTENT_DATA
293 select DM_BIO_PRISON
294 help
295 dm-cache attempts to improve performance of a block device by
296 moving frequently used data to a smaller, higher performance
297 device. Different 'policy' plugins can be used to change the
298 algorithms used to select which blocks are promoted, demoted,
299 cleaned etc. It supports writeback and writethrough modes.
300
301config DM_CACHE_SMQ
302 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
303 depends on DM_CACHE
304 default y
305 help
306 A cache policy that uses a multiqueue ordered by recent hits
307 to select which blocks should be promoted and demoted.
308 This is meant to be a general purpose policy. It prioritises
309 reads over writes. This SMQ policy (vs MQ) offers the promise
310 of less memory utilization, improved performance and increased
311 adaptability in the face of changing workloads.
312
313config DM_WRITECACHE
314 tristate "Writecache target"
315 depends on BLK_DEV_DM
316 help
317 The writecache target caches writes on persistent memory or SSD.
318 It is intended for databases or other programs that need extremely
319 low commit latency.
320
321 The writecache target doesn't cache reads because reads are supposed
322 to be cached in standard RAM.
323
324config DM_EBS
325 tristate "Emulated block size target (EXPERIMENTAL)"
326 depends on BLK_DEV_DM && !HIGHMEM
327 select DM_BUFIO
328 help
329 dm-ebs emulates smaller logical block size on backing devices
330 with larger ones (e.g. 512 byte sectors on 4K native disks).
331
332config DM_ERA
333 tristate "Era target (EXPERIMENTAL)"
334 depends on BLK_DEV_DM
335 default n
336 select DM_PERSISTENT_DATA
337 select DM_BIO_PRISON
338 help
339 dm-era tracks which parts of a block device are written to
340 over time. Useful for maintaining cache coherency when using
341 vendor snapshots.
342
343config DM_CLONE
344 tristate "Clone target (EXPERIMENTAL)"
345 depends on BLK_DEV_DM
346 default n
347 select DM_PERSISTENT_DATA
348 help
349 dm-clone produces a one-to-one copy of an existing, read-only source
350 device into a writable destination device. The cloned device is
351 visible/mountable immediately and the copy of the source device to the
352 destination device happens in the background, in parallel with user
353 I/O.
354
355 If unsure, say N.
356
357config DM_MIRROR
358 tristate "Mirror target"
359 depends on BLK_DEV_DM
360 help
361 Allow volume managers to mirror logical volumes, also
362 needed for live data migration tools such as 'pvmove'.
363
364config DM_LOG_USERSPACE
365 tristate "Mirror userspace logging"
366 depends on DM_MIRROR && NET
367 select CONNECTOR
368 help
369 The userspace logging module provides a mechanism for
370 relaying the dm-dirty-log API to userspace. Log designs
371 which are more suited to userspace implementation (e.g.
372 shared storage logs) or experimental logs can be implemented
373 by leveraging this framework.
374
375config DM_RAID
376 tristate "RAID 1/4/5/6/10 target"
377 depends on BLK_DEV_DM
378 select MD_RAID0
379 select MD_RAID1
380 select MD_RAID10
381 select MD_RAID456
382 select BLK_DEV_MD
383 help
384 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
385
386 A RAID-5 set of N drives with a capacity of C MB per drive provides
387 the capacity of C * (N - 1) MB, and protects against a failure
388 of a single drive. For a given sector (row) number, (N - 1) drives
389 contain data sectors, and one drive contains the parity protection.
390 For a RAID-4 set, the parity blocks are present on a single drive,
391 while a RAID-5 set distributes the parity across the drives in one
392 of the available parity distribution methods.
393
394 A RAID-6 set of N drives with a capacity of C MB per drive
395 provides the capacity of C * (N - 2) MB, and protects
396 against a failure of any two drives. For a given sector
397 (row) number, (N - 2) drives contain data sectors, and two
398 drives contains two independent redundancy syndromes. Like
399 RAID-5, RAID-6 distributes the syndromes across the drives
400 in one of the available parity distribution methods.
401
402config DM_ZERO
403 tristate "Zero target"
404 depends on BLK_DEV_DM
405 help
406 A target that discards writes, and returns all zeroes for
407 reads. Useful in some recovery situations.
408
409config DM_MULTIPATH
410 tristate "Multipath target"
411 depends on BLK_DEV_DM
412 # nasty syntax but means make DM_MULTIPATH independent
413 # of SCSI_DH if the latter isn't defined but if
414 # it is, DM_MULTIPATH must depend on it. We get a build
415 # error if SCSI_DH=m and DM_MULTIPATH=y
416 depends on !SCSI_DH || SCSI
417 help
418 Allow volume managers to support multipath hardware.
419
420config DM_MULTIPATH_QL
421 tristate "I/O Path Selector based on the number of in-flight I/Os"
422 depends on DM_MULTIPATH
423 help
424 This path selector is a dynamic load balancer which selects
425 the path with the least number of in-flight I/Os.
426
427 If unsure, say N.
428
429config DM_MULTIPATH_ST
430 tristate "I/O Path Selector based on the service time"
431 depends on DM_MULTIPATH
432 help
433 This path selector is a dynamic load balancer which selects
434 the path expected to complete the incoming I/O in the shortest
435 time.
436
437 If unsure, say N.
438
439config DM_MULTIPATH_HST
440 tristate "I/O Path Selector based on historical service time"
441 depends on DM_MULTIPATH
442 help
443 This path selector is a dynamic load balancer which selects
444 the path expected to complete the incoming I/O in the shortest
445 time by comparing estimated service time (based on historical
446 service time).
447
448 If unsure, say N.
449
450config DM_MULTIPATH_IOA
451 tristate "I/O Path Selector based on CPU submission"
452 depends on DM_MULTIPATH
453 help
454 This path selector selects the path based on the CPU the IO is
455 executed on and the CPU to path mapping setup at path addition time.
456
457 If unsure, say N.
458
459config DM_DELAY
460 tristate "I/O delaying target"
461 depends on BLK_DEV_DM
462 help
463 A target that delays reads and/or writes and can send
464 them to different devices. Useful for testing.
465
466 If unsure, say N.
467
468config DM_DUST
469 tristate "Bad sector simulation target"
470 depends on BLK_DEV_DM
471 help
472 A target that simulates bad sector behavior.
473 Useful for testing.
474
475 If unsure, say N.
476
477config DM_INIT
478 bool "DM \"dm-mod.create=\" parameter support"
479 depends on BLK_DEV_DM=y
480 help
481 Enable "dm-mod.create=" parameter to create mapped devices at init time.
482 This option is useful to allow mounting rootfs without requiring an
483 initramfs.
484 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
485 format.
486
487 If unsure, say N.
488
489config DM_UEVENT
490 bool "DM uevents"
491 depends on BLK_DEV_DM
492 help
493 Generate udev events for DM events.
494
495config DM_FLAKEY
496 tristate "Flakey target"
497 depends on BLK_DEV_DM
498 help
499 A target that intermittently fails I/O for debugging purposes.
500
501config DM_VERITY
502 tristate "Verity target support"
503 depends on BLK_DEV_DM
504 select CRYPTO
505 select CRYPTO_HASH
506 select DM_BUFIO
507 help
508 This device-mapper target creates a read-only device that
509 transparently validates the data on one underlying device against
510 a pre-generated tree of cryptographic checksums stored on a second
511 device.
512
513 You'll need to activate the digests you're going to use in the
514 cryptoapi configuration.
515
516 To compile this code as a module, choose M here: the module will
517 be called dm-verity.
518
519 If unsure, say N.
520
521config DM_VERITY_VERIFY_ROOTHASH_SIG
522 def_bool n
523 bool "Verity data device root hash signature verification support"
524 depends on DM_VERITY
525 select SYSTEM_DATA_VERIFICATION
526 help
527 Add ability for dm-verity device to be validated if the
528 pre-generated tree of cryptographic checksums passed has a pkcs#7
529 signature file that can validate the roothash of the tree.
530
531 By default, rely on the builtin trusted keyring.
532
533 If unsure, say N.
534
535config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
536 bool "Verity data device root hash signature verification with secondary keyring"
537 depends on DM_VERITY_VERIFY_ROOTHASH_SIG
538 depends on SECONDARY_TRUSTED_KEYRING
539 help
540 Rely on the secondary trusted keyring to verify dm-verity signatures.
541
542 If unsure, say N.
543
544config DM_VERITY_FEC
545 bool "Verity forward error correction support"
546 depends on DM_VERITY
547 select REED_SOLOMON
548 select REED_SOLOMON_DEC8
549 help
550 Add forward error correction support to dm-verity. This option
551 makes it possible to use pre-generated error correction data to
552 recover from corrupted blocks.
553
554 If unsure, say N.
555
556config DM_SWITCH
557 tristate "Switch target support (EXPERIMENTAL)"
558 depends on BLK_DEV_DM
559 help
560 This device-mapper target creates a device that supports an arbitrary
561 mapping of fixed-size regions of I/O across a fixed set of paths.
562 The path used for any specific region can be switched dynamically
563 by sending the target a message.
564
565 To compile this code as a module, choose M here: the module will
566 be called dm-switch.
567
568 If unsure, say N.
569
570config DM_LOG_WRITES
571 tristate "Log writes target support"
572 depends on BLK_DEV_DM
573 help
574 This device-mapper target takes two devices, one device to use
575 normally, one to log all write operations done to the first device.
576 This is for use by file system developers wishing to verify that
577 their fs is writing a consistent file system at all times by allowing
578 them to replay the log in a variety of ways and to check the
579 contents.
580
581 To compile this code as a module, choose M here: the module will
582 be called dm-log-writes.
583
584 If unsure, say N.
585
586config DM_INTEGRITY
587 tristate "Integrity target support"
588 depends on BLK_DEV_DM
589 select BLK_DEV_INTEGRITY
590 select DM_BUFIO
591 select CRYPTO
592 select CRYPTO_SKCIPHER
593 select ASYNC_XOR
594 select DM_AUDIT if AUDIT
595 help
596 This device-mapper target emulates a block device that has
597 additional per-sector tags that can be used for storing
598 integrity information.
599
600 This integrity target is used with the dm-crypt target to
601 provide authenticated disk encryption or it can be used
602 standalone.
603
604 To compile this code as a module, choose M here: the module will
605 be called dm-integrity.
606
607config DM_ZONED
608 tristate "Drive-managed zoned block device target support"
609 depends on BLK_DEV_DM
610 depends on BLK_DEV_ZONED
611 select CRC32
612 help
613 This device-mapper target takes a host-managed or host-aware zoned
614 block device and exposes most of its capacity as a regular block
615 device (drive-managed zoned block device) without any write
616 constraints. This is mainly intended for use with file systems that
617 do not natively support zoned block devices but still want to
618 benefit from the increased capacity offered by SMR disks. Other uses
619 by applications using raw block devices (for example object stores)
620 are also possible.
621
622 To compile this code as a module, choose M here: the module will
623 be called dm-zoned.
624
625 If unsure, say N.
626
627config DM_AUDIT
628 bool "DM audit events"
629 depends on BLK_DEV_DM
630 depends on AUDIT
631 help
632 Generate audit events for device-mapper.
633
634 Enables audit logging of several security relevant events in the
635 particular device-mapper targets, especially the integrity target.
636
637endif # MD